Don't ignore an OpenBSD GPT partition just because the GPT says

it extends beyond the edge of the disk the GPT currently
inhabits. We only care if enough of it is addressable that a
disklabel is accessible.

Brings GPT handling of 'OpenBSD partitions extending too far'
into line with the MBR handling of the same situation.

diff --git a/sys/kern/subr_disk.c b/sys/kern/subr_disk.c
index 5f06c01..483cd7c 100644 (file)
--- a/sys/kern/subr_disk.c
+++ b/sys/kern/subr_disk.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: subr_disk.c,v 1.257 2022/09/02 12:28:12 krw Exp $     */
+/*     $OpenBSD: subr_disk.c,v 1.258 2022/09/02 14:18:47 krw Exp $     */
 /*     $NetBSD: subr_disk.c,v 1.17 1996/03/16 23:17:08 christos Exp $  */
 
 /*
@@ -590,17 +590,16 @@ int
 spoofgpt(struct buf *bp, void (*strat)(struct buf *), const uint8_t *dosbb,
     struct disklabel *lp, daddr_t *partoffp)
 {
-       static const uint8_t     gpt_uuid_openbsd[] = GPT_UUID_OPENBSD;
        struct dos_partition     dp[NDOSPART];
        struct gpt_header        gh;
-       struct uuid              gptype, uuid_openbsd;
+       struct uuid              gptype;
        struct gpt_partition    *gp;
        struct partition        *pp;
-       uint64_t                 lbaend, lbastart;
+       uint64_t                 lbaend, lbastart, labelsec;
        uint64_t                 gpbytes, end, start;
-       daddr_t                  labeloff, partoff;
+       daddr_t                  partoff;
        unsigned int             i, n;
-       int                      error, obsdfound;
+       int                      error, fstype, obsdfound;
        uint32_t                 partnum;
        uint16_t                 sig;
 
@@ -634,7 +633,6 @@ spoofgpt(struct buf *bp, void (*strat)(struct buf *), const uint8_t *dosbb,
        partnum = letoh32(gh.gh_part_num);
 
        n = 'i' - 'a';  /* Start spoofing at 'i', a.k.a. 8. */
-       uuid_dec_be(gpt_uuid_openbsd, &uuid_openbsd);
 
        DL_SETBSTART(lp, lbastart);
        DL_SETBEND(lp, lbaend + 1);
@@ -642,33 +640,41 @@ spoofgpt(struct buf *bp, void (*strat)(struct buf *), const uint8_t *dosbb,
        obsdfound = 0;
        for (i = 0; i < partnum; i++) {
                start = letoh64(gp[i].gp_lba_start);
-               end = letoh64(gp[i].gp_lba_end) + 1;
-               if (start >= end || start < lbastart || end > lbaend + 1)
+               if (start > lbaend || start < lbastart)
+                       continue;
+
+               end = letoh64(gp[i].gp_lba_end);
+               if (start > end)
+                       continue;
+
+               uuid_dec_le(&gp[i].gp_type, &gptype);
+               fstype = gpt_get_fstype(&gptype);
+               if (obsdfound && fstype == FS_BSDFFS)
                        continue;
-               if (obsdfound == 0) {
-                       labeloff = partoff + DOS_LABELSECTOR;
-                       if (labeloff >= DL_SECTOBLK(lp, start) &&
-                           labeloff < DL_SECTOBLK(lp, end))
+
+               if (fstype == FS_BSDFFS) {
+                       obsdfound = 1;
+                       partoff = DL_SECTOBLK(lp, start);
+                       labelsec = DL_BLKTOSEC(lp, partoff + DOS_LABELSECTOR);
+                       if (labelsec > ((end < lbaend) ? end : lbaend))
                                partoff = -1;
+                       DL_SETBSTART(lp, start);
+                       DL_SETBEND(lp, end + 1);
+                       continue;
                }
 
-               uuid_dec_le(&gp[i].gp_type, &gptype);
-               if (memcmp(&gptype, &uuid_openbsd, sizeof(gptype)) == 0) {
-                       if (obsdfound == 0) {
-                               obsdfound = 1;
-                               partoff = DL_SECTOBLK(lp, start);
-                               labeloff = partoff + DOS_LABELSECTOR;
-                               if (labeloff >= DL_SECTOBLK(lp, end))
-                                       partoff = -1;
-                               DL_SETBSTART(lp, start);
-                               DL_SETBEND(lp, end);
-                       }
-               } else if (n < MAXPARTITIONS) {
+               if (partoff != -1) {
+                       labelsec = DL_BLKTOSEC(lp, partoff + DOS_LABELSECTOR);
+                       if (labelsec >= start && labelsec <= end)
+                               partoff = -1;
+               }
+
+               if (n < MAXPARTITIONS && end <= lbaend) {
                        pp = &lp->d_partitions[n];
                        n++;
-                       pp->p_fstype = gpt_get_fstype(&gptype);
+                       pp->p_fstype = fstype;
                        DL_SETPOFFSET(pp, start);
-                       DL_SETPSIZE(pp, end - start);
+                       DL_SETPSIZE(pp, end - start + 1);
                }
        }